High-dose chemotherapy with autologous stem cell support is the current standard procedure in the first-line treatment in younger patients with myeloma fit for intensive treatment. Current practice in Switzerland for stem cell mobilization is the combination of chemotherapy and G-CSF stimulation in myeloma patients fit for high-dose chemotherapy with melphalan and autologous stem cell transplant. For mobilization chemotherapy, a single dose of vinorelbine is commonly used, producing mild myelosuppression. G-CSF is started at day 4 on a daily basis, allowing stem cell apheresis usually at day 8. In a subsequent study, we evaluated the use of pegylated G-CSF given as a single injection at day 4 together with vinorelbine. We found this regimen equally feasible, reliable and allowing collection of stem cells in an equally high percentage. In the current proposal, we suggest to continue this line of research investigating the mobilization using chemotherapy with vinorelbine. We propose to study the feasibility of this mobilization chemotherapy in the absence of growth factors, thus without G-CSF, in combination with Plerixafor.